In the manufacture of tires, and in particular, pneumatic tires for passenger vehicles, rubber tire components are formed of uncured rubber in elongated strip form for subsequent application to a tire building drum prior to curing in a mold. These preassembled tire components for usual pneumatic tires generally consist of a black sidewall area which is joined by a thin abrasion strip to an intermediate innerliner of a generally uniform thickness which then is joined by another abrasion strip to a white sidewall area. The thickness of the white sidewall area of the preassembled tire component is generally thicker than the black sidewall area, which in turn is thicker than the intervening innerliner and abrasion strip areas. This uneven or contoured strip, when viewed in cross section, is extremely troublesome when packaged on rolls for subsequent storage and shipment for further processing in the tire manufacturing procedure. The unevenness or cross-sectional thickness variation results in telescoping conical rolls when wound into roll form which will wrinkle, crush, or distort the preassembled tire components.
Upon wrapping or rolling of these preassembled tire components, formed of an uncured rubber into roll form, a liner material is used to prevent the adjacent layers of the roll from sticking together. Heretofore, this liner material was of a generally uniform cross-sectional configuration intended only to prevent sticking together of the adjacent layers of the rubber tire material. Although this liner material works satisfactorily in preventing sticking of the rubber strip, it does not assist or eliminate the problem of the telescoping conical shaping of the resulting rolled material.
Therefore, the need exists for a contoured liner for use with strip material of varying cross-sectional thickness, and in particular for a preassembled tire component of varying cross-sectional thickness which will prevent crushing or distortion of the rubber material when in roll form, and which will result in a generally cylindrical roll in contrast to the heretofor conical-shaped roll with the resulting problems inherent therewith upon being placed into roll form.
There is no known prior art liner material of which I am aware which achieves these advantages. The following patents are the closest known prior art.
U.S. Pat. No. 1,356,234 discloses a sheet rubber liner which is interleaved with a rolled rubber sheet. The liner can be formed from parchmentized sheet material and is positioned between flat or coiled rubber material.
U.S. Pat. No. 1,543,283 discloses a non-stick liner which is interleaved with a roll of tacky rubber sheet. The liner comprises a woven fabric with a non-tacky surface.
U.S. Pat. No. 1,611,400 discloses a rolled rubber material having a interleaved liner of fabric coated with cellulose xanthate or viscose to prevent the liner from sticking to the rubber.
U.S. Pat. No. 2,639,249 discloses a liner for rubber sheeting which is comprised of a woven fabric treated with a coating composition, and which has a non-tacky portion which is adhered to the rubber.
British Patent No. 651,428 discloses a protective cellulose sheet which can be interleaved with and stripped from rolled or coiled rubber. Although the cellulose plies have varied thicknesses, such thicknesses applies to varied liner thicknesses for each use, rather than to a single liner having various thickness portions in the transverse cross-sectional direction.
Although all of the patents discussed above disclose interleaved liners for coiling or rolling rubber, none of these patents disclose the use of a liner having a non-uniform thickness or gauge as the contoured liner set forth in detail below.